Having a clock signal with 50% duty cycle is extremely important in various semiconductor technologies, including input/output double data rate (“I/O DDR”) and serial/deserial (“SerDes”) interface designs. The performance of logic circuits can highly depend on timings of both positive and negative edges of a clock signal. A 50% duty cycle for a clock signal is especially important in operating circuits at high speed. However, it is difficult to maintain a high-speed clock signal at 50% duty cycle after distributing that clock signal throughout an integrated circuit (“IC”) system due to noise in the IC system. Additionally, the duty cycle of the clock signal cannot be guaranteed under various process, voltage, and temperature (“PVT”) conditions without using additional circuitry such as duty cycle detectors and correctors to adjust the duty cycle to account for PVT errors.
Therefore, it is desirable for new methods, systems, and apparatuses for duty cycle detection to reduce PVT errors in order to achieve a proper resolution for signals used for ICs and other computing system.